(1) Field of the Invention
This invention relates to an improved water neutralizer for raising the pH of household drinking water.
(2) Related Art
It is well-known that excess acids in drinking water can lead to deleterious effects. Such acids can appear in a drinking water system due to a variety of sources. A common source of acids in individually drilled wells is acid leached from rotting leaves and other vegetation into the groundwater system. Typically, these sources of acid can lead to a pH in the water of between about 5.8 and about 6.5. pH levels in this range tend to lead to blue-green stains in water system elements due to reaction of the acid in the water with copper piping and solder.
One method of neutralizing such acid in water which is generally known in the art is to expose the water to a neutralizing mineral, for example calcium carbonate (CaCO.sub.3), for a period of time. Typically, all water entering a dwelling is caused to reside in a tank containing a quantity of this or an equivalent mineral for a period of time. The carbonates are leached into the dwelling water supply, and neutralize the acid. The most common carbonate tanks are elongated cylindrical tanks standing in a vertical position. The neutralizing mineral is disposed in the tank. Water enters the upper end of the tank, passes downwardly through the mineral, and drains through the lower end of the tank.
A common practice is to form the tank of a fiber reinforced plastic ("fiberglass") material. Such tanks have either top-mounted or side-mounted water inlet fittings. As the typical fiberglass tank is relatively thin-walled, it is difficult to provide a seal of integrity between a sidemounted water inlet port fitting and the tank. For this reason, mounting of the water inlet fitting in the end of the tank, where the fiberglass is thicker, is preferred. Suitable fittings are commercially available. Furthermore, from time to time the carbonate supply in the tank must be replenished. This necessitates that a mineral replacement port be provided in the carbonate tank. End-mounting fittings which provide a water inlet connection and a mineral replacement port are commercially available.
It is desirable that the neutralizing mineral in the tank be backflushed at intervals to "fluff" it, that is, to ensure its continued efficiency, remove debris, etc. Automatic controllers for reversing the flow of water for backflushing the mineral for a short period of time, for example, ten minutes, at regular service intervals, for example, once per week, are known. Typically, these controllers and the associated valves are provided near the water inlet fitting. Where the water inlet fitting is affixed to the side of the tank, a leakage problem is commonly presented, as noted above. According to known methods of mounting the backflush control apparatus and associated valves at the end of the tank, complete disassembly of the control and the associated valving may be necessary in order that mineral replenishment can be performed. Since mineral replenishment typically is required at intervals of a year or less, this can present a significant inconvenience and expense to the homeowner.
Another problem of conventional neutralizers is that the neutralizing minerals commonly used are relatively inferior. One type of mineral which is commonly used comprises approximately 74% calcium carbonate, the remainder being silicates and manganese and magnesium minerals and the like. The inventor's understanding is that in typical use, such minerals require replenishment at intervals of no more than about one year. Replenishment at such an interval is inconvenient, as it requires a visit by a plumber.
Another deficiency of conventional neutralizers involves their method of assembly, and adds to their cost. It is common to employ a mixture of metal and plastic tubing and fittings. The plastic is ordinarily polyvinylchloride and the metal either copper or brass. Such mixed materials are usually sealed to one another at joints using a "Teflon" tape. (Teflon is a trademark of E. I. DuPont de Nemours and Company, Wilmington, Del.) More recently, Teflon pipe sealing compounds have become available, in which the Teflon is disposed in a thick, gluey vehicle. The sealing compound is applied to the threads of the male member of the joint using a brush.
Use of the Teflon tape can cause a problem in that a tradeoff is made between the amount of the tape used and the torque applied to the joint to obtain a leak-free connection. If one uses a large and hence relatively costly amount of tape, the joint need not be tightened extremely tight to be leakproof; if a lesser amount of tape is used, the joint must be made so tight that plastic fittings tend to rupture. Use of the tape is also relatively time-consuming and requires some little skill on the part of the installer. Brush application of the Teflon-based sealing compound is messy, time-consuming, and is also not foolproof.
Finally, certain known water neutralizers do not provide suitable means for directing water flow within the mineral bed both in normal use and upon backflush, so that the mineral bed is not used to its maximum advantage.